I mean, they might just be a class of frauds that are currently legal thanks to lack of will to close a particular loophole that permits their existence. And it's not as if they don't receive legal penalties all the time:
This sub-thread is very amusing. All you people saying if it was fraud there would be lawsuits. Guess what, there are tons of lawsuits against these companies and also settlements. And vc doesn't care! Look at the genius. Look at WeWork and Adam Neumann. Many people saw it was impossible to make money and meet their valuation.
https://heavy.com/news/2020/08/herbalife/
https://www.cs.cmu.edu/~dst/Amway/AUS/hanrahan.htm